1. Field of the Invention
The present invention relates to a dynamic video communication evaluation equipment, and more particularly to a dynamic video communication evaluation equipment for evaluating dynamic video code and protocol used to transmit and receive digital dynamic video data.
2. Description of the Related Art
Recently, wide area computer networks such as Internet have been developed, through which various types of data have been exchanged in a large scale. Conventionally, due to the bottleneck of computer processing speed and lower network throughput, only character information or compressed still video image having comparatively less amount of information were allowed to be exchanged.
However, thanks to recent rapid enhancement of the computer processing speed and enhanced network speed, dynamic video image having a large amount of information have become exchanged. Hereafter, it is unavoidable that the dynamic video image will be generally transferred without an analog signal via a TV set, etc. but with a digital data which can be processed by computers, which is however not limited to the above mentioned Internet, through various networks.
Under the background, it is very important to estimate the quality such as transfer speed of dynamic video data on the network for efficient use of the network resources.
An apparatus for evaluating the dynamic video code and protocol in a dynamic video communication has been proposed by the same inventor, for example, as disclosed in application Ser. No. 09/216,814 filed Aug. 11, 1997 (and corresponding U.S. Ser. No. 09/132,403 filed Aug. 11, 1998), the technology of which will be described hereinafter.
First of all, technical terms used in this application will be defined as follows
A communication protocol is a protocol on communication which is also used in a communication other than a dynamic video such as UDP/IP(User Diagram Protocol/Internet Protocol), and also includes a communication for performing a negotiation before data is transmitted and received between a transmitter and a receiver.
A dynamic video coding method is a protocol relating to a dynamic video code and it includes transmission/reception, decoding indication intended for communication of the dynamic video, and regulations which have determined between network equipment.
For example, there are MPEG (ISO/IEC-11172), MPEG-2 ISO/IEC-13818), MPEG-4 (ISO/IEC-14496), in accordance with ISO (International Organization for Standardization), IEC (International Electromechanical Commission), and ITU (International Telecommunication Union) recommendations H. 320, H. 324, H. 261, and H. 263.
The standardization and recommendations set forth above describe a combination of multiple dynamic video coding methods. For example, there is a dynamic coding method such as a directional estimation method and a unidirectional estimation method wherein they are used commonly to the MPEG, MPED-2, MPED-4 and H. 263.
Further, a dynamic video communication protocol is a protocol for use in a dynamic video communication and it is used for a combination of the dynamic video coding method and the communication protocol. For example, it is such a case that a data stream produced in accordance with the MPEG is transmitted with packet conforming to the UDP/IP.
Then uses of the dynamic video communication protocol will now be described. In the. dynamic video communication protocol, the optimum protocol is diversified depending on the utilization object or the utilization condition of the dynamic video communication. There are various types such as a method that is high in coding rate with small coding amount, a method that is short in coding processing delay time, and a method that is unsusceptible to the influence of the transmission error.
A processing of the dynamic video communication protocol including coding/decoding processing in the transmitter and receiver of the dynamic video communication enables a software processing because a processing speed of a CPU (central processing unit) provided in the equipment such as transmitter/receiver is improved. Further, since the software is easily distributed via a network, the dynamic video communication protocol can be easily changed by the transmitter/receiver.
Under the circumstances, it is important to select and utilize a dynamic video communication protocol in accordance with a utilization object and a utilization network among various dynamic video communication protocols. Accordingly, there is xe2x80x9ca dynamic video communication control equipmentxe2x80x9d as disclosed in Japanese Patent Application No. 09-216814 by the same inventor of this application as an example for providing means for selecting a dynamic video communication protocol for evaluating a dynamic image quality in a receiver or a relay to assure high quality. The dynamic video communication control equipment includes means for obtaining various hierarchy and kinds of information from the receiver or the relay, and executes analysis processing to calculate the dynamic video image quality parameters.
The communication protocol video image quality parameters calculate values indicating 5 categories, however in this application, a conventional technique will be explained while dynamic video communication control equipment is arranged for simplification and the dynamic video communication protocol video image quality parameters are served as a single image quality evaluation value with a simplified construction.
FIG. 7 is a block diagram showing the construction of a conventional dynamic video communication control equipment.
As shown in FIG. 7, in the dynamic video communication control equipment, a dynamic video code transmitter 10 and a dynamic video code receiver 30 are respectively connected to a network 20, and a dynamic video communication analysis equipment 40 is connected to the dynamic video code receiver 30.
The dynamic video code transmitter 10 transmits a dynamic video code to the dynamic video code receiver 30 via the network 20. The dynamic video code and a communication protocol received by the dynamic video code receiver 30 influence image quality in the dynamic video code receiver 30. The dynamic video code receiver 30 transmits dynamic video code and the communication protocol data that are received thereby to the dynamic video communication analysis equipment 40 as quality data in view of evaluating quality of received code and data.
The dynamic video communication analysis equipment 40 comprises multiple analysis processing parts 42a, 42b, . . . of different types of methods. Respective analysis processing parts 42a, 42b, . . . receive quality data outputted from the dynamic video code receiver 30, and analyze based on this quality data, and then output the analysis result as an image evaluation value.
There is a case where all the analysis processing parts 42a, . . . receive common quality data, and there is another case where the respective analysis processing parts 42a, 42b, . . . receive different image quality data.
There are provided image quality evaluation value memories 44a, 44b, . . . at the rear stages of respective analysis processing parts 42a, . . . The image quality evaluation value memories 44a, 44b, . . . respectively temporality store image evaluation values outputted from the analysis processing parts 42a, 42b, . . . There is provided an indication part 46 at the rear stages of the image quality evaluation value memories 44a, 44b, . . . The indication part 46 has an indication unit such as a display and indicates image evaluation values respectively outputted from the image quality evaluation value memories 44a, 44b, . . . 
The problems of the conventional technique will be now described although the dynamic video communication control equipment has been described above.
Described next is a case where the transmission timing is controlled under the condition that where a real time communication of a dynamic video code, namely, a code reception for preserving time characteristics of a dynamic video is in time when coding, and the amount of buffering of the imaginary code that waits decoding at a decoding part is not continues increased.
In the conventional dynamic video communication evaluation equipment, the analysis processing method is normally performed by directly comparing an original image with a reception image, or in the case of analyzing image characteristics by constructing the image, the analysis processing scale becomes larger than a decode processing scale. Accordingly, there is a case that the analysis processing is not in time for the dynamic video code to be received at a processing speed that is equivalent to or lower than a decode processing speed.
In this case if the analysis processing is performed while exceeding a storage allowable amount, there is employed a method to intermittently take the codes to be analyzed therein.
If this method is employed, it is necessary to employ a method for estimate dynamic video image quality for evaluating the entire dynamic video image because the codes to be analyzed are a part thereof Because of the estimation, the dynamic video evaluation values outputted from the analysis processing parts are those which are likely to be certain, and hence estimation error range is accompanied therewith.
However, according to this conventional method, the estimation error is not indicated, leading to a problem that a rough estimation value and an estimation value with high precision value are not differentiated from each other.
Further, in the case having multiple analysis processing parts 42a, 42b, . . . of different types of methods as shown in FIG. 7, time for outputting the analysis result by the analysis processing parts 42a, 42b, . . . , and cost by the analysis processing parts 42a, 42b, . . . are diversified. If a communication cost involved in the transmission of the quality data is required, the communication time and analysis processing time are diversified, leading to various costs necessary for communication costs.
It is a general tendency to obtain a result in small estimation error as the analysis takes time and cost. There is a case where no correlation exists between the time and cost involved in an analysis and the obtained estimation error.
Accordingly, it is not always expected that the estimation error gradually decreases as the analysis result is obtained later.
Assuming that, quality data required for analysis for the analysis processing part processing part 42a to perform analysis of 1 k byte, and transmission speed is 0.7 seconds, and the time required for outputting a processing result at the analysis processing part processing part 42a upon completion of the transmission is 0.3 seconds.
Meanwhile, assuming that, quality data required for the analysis processing par 42b is 1M byte, and the transmission speed is 10 minutes, and the time required for outputting the processing result at the analysis processing part 42b upon completion of the transmission is 50 minutes.
Still further, assume that as a result of taking time and cost for the preparation of data although quality data needed for analyzing at another analysis processing part, not shown, is only dynamic video code 10 bytes, it takes 9.9 seconds for transmission, and 0.1 second for outputting processing results from the analysis processing part upon completion of the transmission.
Time required from the start of image data transmission to the output of analysis results is 1 second at the analysis processing part 42a, 1 hour at the analysis processing part 42b, and 10 seconds at another analysis processing part, not shown.
Considering that costs involved in communication is proportional to the amount of data, the communication costs involved in respective analysis processing parts are 10 yen at the analysis processing part 42a, 10,000 yen at the analysis processing part 42b, and 0.1 yen at the analysis processing part, not shown, assuming that it costs 1 yen per 100 bytes.
The respective analysis processing parts include estimation, and this estimation is not largely different therebetween compared with the amount of input data, the time and cost as set forth above.
For users of the dynamic video communication analysis equipment to perform the evaluation of the dynamic video image quality, under the limited condition of time or cost, it is required to determine whether an estimation error contained in an analysis result to be outputted is justified in terms of time or cost.
Since, however, it is not expected due to the above mentioned limitation either to perform an analysis for a long time to obtain a result with smaller estimation error using multiple analysis processing methods, or to wait for processing results by means of expensive processing method, there was a problem that users could not verify whether the expected analysis result was obtained or not.
Moreover, although for users of the above mentioned dynamic video communication analysis equipment who intend to evaluate the dynamic video image quality and have an allowance criteria in advance for the estimation error that is achieved, it may be desirable to terminate the dynamic video image quality evaluation at the time when any estimation error from multiple analysis processings which is under the allowance criteria for the first time is outputted, there was likewise a problem that the users could not determine whether the desired result is achieved or not as a analysis result.
Further, when there is no large difference between estimation errors from multiple analysis processings, it may be desired to terminate the evaluation of dynamic video image quality, according to the distribution of estimation values from multiple analysis processings, if the distribution shows a concentration about a particular value. However, the users could not verify whether the expected analysis result was obtained or not as well.
The present invention intends to solve the above mentioned problems by providing dynamic video communication evaluation equipment for allowing users to achieve a dynamic video image quality evaluation. More specifically, the present invention intends to provide the dynamic video communication evaluation equipment which allows dynamic video image quality evaluation according to the following various users"" judgment criterion:
(1) differentiating between a rough estimation value and an estimation value by high precision analysis
(2) differentiating between an analysis processing with a rough estimation and that with a high precision
(3) achieving an analysis result efficiently at a limited time
(4) achieving an analysis result efficiently at a limited cost
(5) terminating a dynamic video image quality evaluation processing while directly viewing the range of estimation value of analysis result from multiple analysis processing methods
(6) terminating a dynamic video image quality evaluation when an allowable analysis result is firstly obtained against the predefined allowance criteria of estimation error.
To achieve the above objects, the dynamic video communication evaluation equipment is characterized in comprising a dynamic video code transmitter which transmits a dynamic video as a digital dynamic video code via a network by selecting it from multiple dynamic video coding methods and multiple communication protocols, a dynamic video code receiver for receiving and decoding the digital dynamic video code which are transmitted via the network conforming to the video coding method and communication protocol used for the digital dynamic video code, and a dynamic video communication analysis equipment composed of analysis means which calculates both of estimation value of dynamic video image quality evaluation value and an error range of said estimation value according to said dynamic video coding method and said communication protocol, and indication means to indicate said estimation value and said error range.
Further, the dynamic video communication analysis equipment according to the present invention is characterized in comprising multiple analysis means of different types which analyze said dynamic video coding method and said communication protocol that are received, estimation value storage means which is provided in each of said multiple analysis means and stores therein the estimation value calculated by the multiple analysis means, and error range storage means which is implemented in each of said multiple analysis means and stores said error range calculated by said analysis means.
Further, the dynamic video communication analysis equipment according to the present invention is characterized in calculating in advance each processing time for each of the multiple analysis means, then performs the processing in the order of shorter processing time.
Further, the dynamic video communication analysis equipment according to the present invention is characterized in calculating in advance each processing cost for each of the multiple analysis means, then performs the processing in the order of smaller processing cost.
Further, the indication means according to the present invention is characterized in updating the indication by updating the estimation value stored in said estimation value storage means or updating the error range stored in said error range storage means.
Further, the indication means according to the present invention is characterized in indicating all of said estimation values stored in said estimation value storage means.
Further, the indication means according to the present invention is characterized in indicating both of the estimation value stored in the estimation value storage means corresponding to the analysis means related to the error range storage means which stores the smallest error range, and the error range stored in said error range storage means.
Further, the said dynamic video communication analysis equipment according to the present invention is characterized in including an output means for outputting the estimation value and the error range.